Let The Angels Commit
by Lizzie9
Summary: The ultimate betrayal. A fall from grace. Will it lead to love or leave them all alone? An alternate universe exploration of the Mark, Addison, Meredith, Derek love rhombus.
1. Chapter 1

**Title: Let The Angels Commit**

**Authors: Sara And Lizzie**

**Rating: T for language, mild sex**

**Disclaimer: If we owned Grey's the season finale would not have sucked so much. **

**Summary: AU. Meredith is starting medical school in New York City. Her fiancé, Mark Sloan, is starting his internship with his two best friends, Derek and Addison in New York City. Mer and Mark are set to get married in November, and Addison thinks it's any day now Derek will pop the question. But Derek and Mer fall for each other. An alternate universe exploration of the Love rhombus created by mer, der, addie and mark. **

**Author's Note: We PROMISE to update our other stuff. But we've had this idea for ages and couldnt keep from starting it. **

**REVIEW.**

_We spend so much time planning for the future. We want control over every detail. We want to think we can know exactly what's going to happen. But the truth is the only thing we can predict about the future is that it's unpredictable. Life is full of surprises, and sometimes it's only when we think we know exactly what the future holds that we encounter what will change our lives._

Meredith Grey stood, uncertainly in the airport surrounded by her best friends. She tucked a piece of hair behind her ear and smiled at them uncertainly, ready to begin this new chapter of her life, but not ready to leave the old one behind.

"You're leaving." Cristina said bluntly. "Oh my God, who the hell told you to go to med school in New York?" she asked.

Meredith smiled at her friend. They had been over this. She was from Seattle, carted off to New York when her mother divorced her father and married Richard Webber. Richard's contract had recently run out at Mount Sinai hospital, and last spring he returned to Seattle Grace as chief.

Her undergrad at Dartmouth had been a blur. Only one of her four best friends had been there with her. They had all met at summer camp in Lake Tahoe when they were all eight years old. Cristina and Meredith's parents sent them there because they could; it was convenient, and their parents were busy. George, Izzie and Alex's parents had sent them there on scholarships.

The five of them were different, but they were all intertwined inextricably in each other's lives. "NYU." Cristina scoffed. "I wasn't aware that they even had a medical school. And you're getting married. Oh my God, Mer. You're going to have babies, go soft, and then I'll have to visit you in dermatology, not perform standstills with you."

Meredith rolled her eyes. "We talked about that, and children are not in the cards for a long time. Getting married isn't the worst thing that could happen to a girl." She said with a grin.

"Especially not with a husband like that." Izzie piped up, grinning mischievously. Meredith sighed and looked out the windows of the airport, her final glimpse of the Space Needle. They had spent the summer between college and medical school in Seattle, a blissful three months of rain, bars and lurking around Seattle Grace.

"Mer, he's starting his intern year. He's not going to have any time for you." Cristina protested. "You could come to Stanford with me…" she trailed off.

Meredith shook her head. "I'm going to NYU. I'm getting married. But we'll all come back right? Just like we promised." She thought fondly back to the night they sat in the bar across the street from Seattle Grace, deciding on two things; to get drunk out of their minds, and that they would return to Seattle for their internships.

"We'll come back." George promised. "Intern year, residency. It's all happening here."

Alex rolled his eyes behind George's back and grinned at Meredith, pulling her into a hug. "Kick ass, Grey." He said. "And tell that boyfriend of yours to treat you like gold, or I'll kick_ his_ ass." Meredith smiled and nodded.

She hugged George next. "Good luck, George." She whispered to him, squeezing his hand. She turned to a tearful Izzie.

"Mer, you're getting married." She wailed. Meredith smiled and embraced her friend tightly.

"Iz, you can help plan my wedding." She promised. "We'll email. He's going to be so busy. And we're getting married in November, which is so soon, so it's just going to be you and me on planning patrol all right?" Izzie nodded tearfully and pulled away.

Meredith took a deep breath and turned to Cristina. "I promise no babies." She said quickly. "And lots of visits. And you're going to be my maid of honor whether you like it or not." She snapped.

"Don't hug me." Her friend said stubbornly.

"Cristina…"

"I mean it. Don't even think about…" she was cut off as Meredith pulled her into a hug. Cristina rolled her eyes and squawked in protest, but wrapped her arms around her best friend anyway. "Keep your fiancé in line, or I'll perform experimental surgery on him." She muttered. Meredith smiled and wiped away a few tears that had formed in the corner of her eyes.

"This is final boarding call for Flight 259 to JFK. All passengers board at gate 17A." Crackled a voice over the loudspeaker. Meredith took a deep breath and gathered her carry on luggage.

"I'll see you all soon." She promised, backing towards the gate. She smiled one last time, and disappeared down the ramp, onto the airplane that was going to take her to New York City.

* * *

It was a long flight, but it gave her time to think. Everything was happening so fast. She was 22, and about to be married, which terrified her. Her engagement, her fiancé, medical school, his internship at the hospital where her step father used to be chief and her mother used to be an attending surgeon, it flew around her mind as the plane touched down.

As she strode off the plane into John F. Kennedy Airport, the buzz of New York City overtook her. She felt a rush of anticipation and a sense of foreboding, like she had no idea what the coming months would bring.

Across the airport, she spotted a familiar looking figure. She squealed and broke into a run. She was a few feet from him when she dropped her bags; she jumped into his arms as she reached him. Her legs hooked around his as their lips met.

"Meredith, I missed you." He breathed into her hair.

"I missed you too, baby." She said. She lifted her eyes over his shoulder, and stared into the intense, deep blue eyes of his best friend, Derek Shepherd. She smiled, but her insides were twisting with something she had never felt before.

Her sense of foreboding came back, only this time she knew why. "Welcome to New York!" he said in her ear.

She rolled her eyes. He sometimes forgot he didn't own the city. "Mark, I'm from New York." She said, earning a private smile from Derek. "I met you here."

"Whatever." He said kissing her again. "Only three months." He said, referring to their wedding. She nodded, smiling, but her eyes never left those of Derek Shepherd.

_Life is funny like that. Just when you think that you've got it all figured out, when you're sure that nothing can get in the way of your plans, life throws you a curve ball. _


	2. Chapter 2

**Title: Let The Angels Commit**

**Authors: Sara And Lizzie**

**Rating: T for language, mild sex**

**Disclaimer: If we owned Grey's the season finale would not have sucked so much. **

**Summary: AU. Meredith is starting medical school in New York City. Her fiancé, Mark Sloan, is starting his internship with his two best friends, Derek and Addison in New York City. Mer and Mark are set to get married in November, and Addison thinks it's any day now Derek will pop the question. But Derek and Mer fall for each other. An alternate universe exploration of the Love rhombus created by mer, der, addie and mark. **

**Author's Note: Okay, we're trying to update everything. REALLY TRYING. Here we're just establishing that everyone is messed up in the head. Things will pick up.**

**REVIEW.**

_Everyone here is wondering what it's like to be with somebody else._

Derek sat in the back seat of Mark's Land Rover, staring out the window, trying to ignore the sound of Meredith's voice. He had always thought she was pretty. Beautiful. Gorgeous, he admitted to himself. Simplistically gorgeous in a way Addison was not. He had always thought that, but he had never felt anything in his life as powerful as he had when she locked eyes with him over Mark's shoulder.

Focusing on New York from the car window helped him block out her excited tones, her adorable giggle. After blocks of mindless staring, he tuned back in. "Mer, this is amazing." Mark said. "You're going to have to tough it out, rooming with Derek and me for awhile, but we'll start looking for an apartment as soon as I've got time." Meredith froze, that detail having escaped her. Living with Mark was one thing, but after the exchange in the airport, living with Mark and Derek was an entirely different story.

She smiled at Mark. "I can start the search." She offered. She swallowed and cleared her throat. "What exactly are your schedules boys?" she asked, her voice teasing.

Derek smiled. "I'm mostly days. With a couple of overnights." He said. Mark switched on his turn signal and switched into another lane, honking at the taxi in front of him.

"Addison and I are mostly nights." He told her. "With a couple of days for good measure. The joys of the intern year."

"My classes are during the day." Meredith pointed out. Mark leaned in and kissed her cheek.

"So Derek can keep you company at night. He can show you around the city."

"I'm from the city;" Meredith said at the exact moment that Derek cleared his throat.

"She's from New York." He pointed out in unison.

Mark grinned. "See? You guys will be fine." Meredith frowned. "Come on baby," Mark said. "You knew this was the deal. We'll still have time, I promise." Meredith smiled up at him and nodded, before turning in her seat to grin at Derek.

"It's just you and me, kid." She quipped. Derek laughed, but the sound died as their eyes locked again, sending electric shocks down Meredith's spine and making Derek's head spin. Meredith broke the gaze, averting her eyes to examine her fingernails. "How's Addison?" she asked softly.

* * *

Addison Forbes Montgomery stepped out of the shower and wrapped a plush Egyptian cotton towel around her body. She sighed, plugged in her hair dryer and began the ritual that would make her red hair fall in a glossy curtain around her perfectly made up porcelain face, her alabaster skin shimmer and her body look fantastic. Yet, even with the products, the clothes and the classically aristocratic good looks, it didn't seem to be enough for Derek.

The past few weeks he had been disconnected, withdrawn. She shook her head to clear the bad thoughts away. They were about to start their intern year, begin their careers. It had to be nerves. With Derek's father being who he was, Derek had some big shoes to fill, and having Mark move Meredith into the apartment they shared in SoHo couldn't have been helping. Addison had half a mind to offer to let Derek move into her Upper East Side apartment, but she was waiting for the moment he dropped to one knee and finally asked her to marry him.

The fact that Mark had done so first was unsettling. Mark Sloan. Addison closed her eyes tightly, squeezing them shut tightly, as if that would block out all the thoughts she shouldn't have been thinking about her boyfriend's best friend. Instead, she focused on Meredith and her jeans and sweaters, her casual demeanor and how wrong she was for Mark.

Addison pulled on her obscenely expensive lingerie and clothing, deep in thought. She liked Meredith, liked her a lot even. She just wasn't the girl for Mark.

* * *

The four of them sat in the trendy downtown restaurant, sipping drinks and waiting for food in the way only New Yorkers could. Conversation flowed easily, the talking, the teasing and joking coming naturally.

"How are your Mom and Richard?" Addison asked Meredith.

"Happy to be back in Seattle." She said.

"I can't imagine why." Mark said, making a face. "Leaving Manhattan for all of that…rain." Meredith stayed silent, choosing not tell him that she had every intention of moving back for her internship.

"I love Seattle." Derek said. Meredith grinned at him.

"Mom and Richard are coming out for that conference in October." She said. "Richard promised to get you guys all off on the same night so they can take us to dinner."

"And I'll be they're just thrilled to know its mere months until this one will be joining the family." She said, reaching over and pinching Mark's cheek.

He grinned his trademark smile. "This handsome, talented doctor? They're elated."

Meredith rolled her eyes. "What is the handsome, talented doctor doing on his fiancée's last day before classes?" she asked.

"Addie and I doing a day shift. Five thirty to twelve." He looked at Addison and shuddered.

Meredith averted her eyes and shrugged. "I'll unpack." She said, her voice light. Mark shook his head.

"Hang out with Derek." Meredith looked at Derek uncertainly.

"You mind, Der?" she asked. He smiled at the way she cut off his name.

"Absolutely not. I'd love it."

She smiled broadly, her eyes sparkling. "Okay." She said softly.

"Okay." He whispered back.

* * *

It was well past midnight, but even the sounds of his I-pod in his ears couldn't drown out the sounds coming from Mark's bedroom. Derek had expected this, had grown accustomed to a trail of women making loud noises in the pre- Meredith years, but this was somehow different.

Something about the idea of Mark touching Meredith's bare skin made Derek uneasy. He was so antsy, he felt ready to crawl out of his own skin. His rolled out of bed, pulled on his jeans and left the apartment. He hailed a cab and directed it to Addison's apartment on the Upper East Side. Her apartment was gorgeous, but in her eyes, paled in comparison to her family's impressive brownstone on Museum Row.

He used his key to get inside and slipped into bed with her. She rolled over to face him and blinked sleepily. "Derek, what are you doing here?" she murmured.

"Missed you." He lied, wrapping his arms around her and closing his eyes. She snuggled into his arms and smiled to herself. Everything would be just fine.


	3. Chapter 3

Meredith Grey stood, uncertainly in the airport surrounded by her best friends

**Title: Let The Angels Commit**

**Authors: Sara And Lizzie**

**Rating: T for language, mild sex**

**Disclaimer: If we owned Grey's the season finale would not have sucked so much. **

**Summary: AU. Meredith is starting medical school in New York City. Her fiancé, Mark Sloan, is starting his internship with his two best friends, Derek and Addison in New York City. Mer and Mark are set to get married in November, and Addison thinks it's any day now Derek will pop the question. But Derek and Mer fall for each other. An alternate universe exploration of the Love rhombus created by mer, der, addie and mark. **

**Author's Note: Okay, we SUCK. Seriously. But finals happened, and things have been crazy, but we are really WE SWEAR going to update everything. And frequently. **

**REVIEW.**

_Your lipstick, his collar, don't bother angel._

"I don't know." Meredith said into her phone as she climbed the stairs to the ninth floor of the building to enter Derek and Mark's apartment. She still felt like a guest there.

"You don't know how things are going?" Cristina demanded. "How do you not know how things are going?"

"Things are fine. I just…" she trailed off.

"You just what? Come on Mer, out with it. I haven't got years."

"I never see Mark. I'm in school during the day. He works at nights. I've been spending most of my time with Derek."

"So your super hot fiancé is actually a workaholic, and he thinks it's safe to leave you alone with Dr. McDreamy?" Meredith pulled open the door to their floor just as the elevator dinged down the hall. Rolling her eyes at both the erratic elevator and Cristina, she searched for the words to mollify her friend.

"Dr. McDreamy?" she repeated. "Please. It's Derek. We don't spend that much time together. Besides…." She trailed off again and coughed, pulling her keys out of her bag. She opened the door and was hit simultaneously and was the sound of The Shins and the smell of food. "I have to go." She said, clicking it off, and shoving it in her bag.

"What is this?" she asked Derek, who was clad in his apron, standing over the stove. She couldn't keep the smile off of her face as he handed her a glass of wine.

"He's not getting off early, Mer." Derek said. "I knew you'd be disappointed so…" he shrugged.

"You made dinner because you thought I'd be disappointed?"

"Aren't you?" _Not if I'm with you_. She shook her head slightly, as if she could chase the thoughts away with the motion.

"This is great, Der." She bit her lip and arched an eyebrow. "The Shins?" Before he could reply, she reached for his I-Home and hit the next button, and the unmistakable beginning of Billy Joel's Uptown Girl came on. She grinned at him. "That's more like it. Is the Clash coming next?"

Derek laughed. "If you want dinner, you'll leave The Clash alone." She settled into a stool at the bar in their kitchen and sipped her wine, smiling as she watched Derek cook.

"Fair enough." She agreed.

* * *

Cristina tossed her phone onto the couch next to her. She had called Meredith half a dozen times since she had ended their call, but she wasn't picking up. Cristina considered their conversation carefully, and picked up her Blackberry again, checking her schedule. She bit her lip and dialed Izzie.

"Cristina!" Izzie squealed into the phone.

Cristina's face screwed into a look of disgust. "Please, Barbie, my eardrums are bleeding."

"Sorry!" Izzie said. Cristina could practically see her tucking loose strands of hair behind her ears, something she always did when she was sheepish.

"We need to talk about Meredith." Cristina said. "I just talked to her. She's spending all of her time with Derek."

"So?" Izzie asked. "She knew McSteamy was going to be busy. I'm sure she's dealing."

"Iz, remember the way she looked at Derek? When we first met them?" Cristina sighed, voicing her suspicions out loud. "Do we really want Meredith to be in this situation?"

"An excellent point." Izzie conceded.

"I'm thinking of flying out there. Next weekend. You in?"

It was Izzie's turn to sigh. "I'm shooting an ad." She confessed, waiting for Cristina to call her Dr. Model. "And I couldn't afford it anyway."

"I'll give you a full report." Cristina assured her.

* * *

Addison's heart was racing. The last time they were alone, this close, he had kissed her. A heart stopping, life altering kiss that left her breathless. And after that, they hadn't discussed it. Nothing had changed. He was engaged, she wanted to be, and he kissed her and they pretended like it never happened.

She wanted him to kiss her again. She had been careful; made sure he had seen her duck into this dark linen closet. Now she was surveying the shelves, pretending to look for something while he leaned against the close door, arms crossed over his chest, smirking at her.

"Addison." He said. She slowly turned her head to look at him. He pulled her to him roughly and kissed her. She hesitated for a fraction of a second before kissing him back. Addison's hands seemed to have a mind of their own. Her fingers, shaking slightly, untied his scrubs and slid down the front of his pants. His breath hitched as she touched him, and he broke the kiss, pulled back and stared at her.

"Fuck it." He muttered. He pulled her scrub top off in one fluid motion. Pressing his lips to hers again, their clothes came off and landed on the linen closet floor as they joined together.


	4. Chapter 4

**Title: Let The Angels Commit**

**Authors: Sara And Lizzie**

**Rating: T for language, mild sex**

**Disclaimer: If we owned Grey's the season finale would not have sucked so much. **

**Summary: AU. Meredith is starting medical school in New York City. Her fiancé, Mark Sloan, is starting his internship with his two best friends, Derek and Addison in New York City. Mer and Mark are set to get married in November, and Addison thinks it's any day now Derek will pop the question. But Derek and Mer fall for each other. An alternate universe exploration of the Love rhombus created by mer, der, addie and mark. **

**Author's Note: Okay, we SUCK. Seriously. But things have been crazy, but we are really going to update everything. And frequently. **

**REVIEW.**

_Oh you're a gambling man, but love is a losing hand. _

The guilt. When Addison let Mark tear her clothes off in that supply closet, there had been a million thoughts going through her head, but she hadn't considered the guilt. At first it had been unbearable, consuming her, suffocating her.

And then it shifted. And the more she replayed the events of that day in her mind, the more she remembered how she felt, the more she seemed to rise above the guilt. She and Mark had not discussed it; they had simply fallen back into their usual banter and working demeanor.

But as much as everything had stayed the same, everything had changed. All of their interactions were charged. Each time she looked at him, it felt like electricity replaced the blood in her veins. So Mark Sloan was as good as they all said he was. Addison hated feeling like his latest conquest, but something inside of her told her she was something more.

And then there was Derek. And Meredith. She loved Derek. Any day now, he would propose to her and that would be the end of this. It had to be. But as Addison walked through Central Park on her way to Lennox Hill, thoughts of Derek and Meredith faded, and were replaced by the question of when it was going to happen again. She slowed and focused on two figures across the park. They were silhouettes against the fading light of day. There was a small girl walking backwards in front of a man.

Addison felt a small smile grace her face as the girl stumbled and the man reached out to steady her, without thinking. He held her elbows and the girl gestured, talking. Her faint laughter tinkled across the park. The guy she was with made a motion and the girl jumped, running away from him and laughing. Addison sighed; they were obviously in love with each other. She imagined that their relationship was straightforward, simple and real. That was all she wanted.

* * *

"Derek do it." Meredith pleaded, walking backwards in front of him. "You don't always need to fall asleep in front of the Daily Show."

Derek grinned. He was going to go wherever she asked him to, but she looked so cute when she was begging, he hadn't admitted that yet. "What do you want to do?" he asked, forcing himself to sound unenthusiastic.

"Nothing big." She said quickly. "Low key. Let's just go to a bar and drink too much tequila." Derek laughed, and she grinned at him, stumbling a bit. He reach out instinctively to steady her.

"Easy there ace." He said easily. He held her by the elbows and smiled. "Let's do it." He said. Meredith began talking quickly, gesturing excitedly. Derek playfully mocked her, removing one of his hands and imitating her gestures.

Meredith laughed. "Don't you mock me, Derek Shepherd." She said, jumping back and running a few steps in front of him. She wanted to skip. She was in Central Park at sunset making plans with this perfect guy. Thoughts of her fiancé who was probably just arriving at work faded completely from her mind.

As the sun slipped below the horizon, Meredith caught a glint of red hair across the park, and thought of Addison for the first time all night. A faint surge of guilt bubbled inside of her, but she pushed it down. She wasn't doing anything wrong.

* * *

Two hours later, she was drunk. A playful, room spinning, giggly kind of drunk. She looked at the tower she had made out of empty shot glasses in front of her. "Catch up, old man." She teased Derek. He opened his mouth to respond when someone bumped from behind, pushing her into him. His hand circled the small of her back protectively.

"Sorry sugar." Said the leering middle age man who had pushed her. Meredith raised her eyebrows at him. "You here alone?" the man asked, his eyes traveling to the V neck of her t-shirt.

"She's with me." Derek said strongly. Meredith looked at him, surprised. He shrugged almost sheepishly and rolled his eyes and the guy. Meredith tried, but couldn't suppress her small, wistful smile.

"Thanks," she said, "Mark probably wouldn't have bothered. He's not bothering with me a whole lot these days." Derek looked down, unsure of what to say. He could have killed Mark for doing this to her. "Can I tell you something?" Meredith asked, wishing she could stop herself from talking. Derek nodded.

"I made a promise," she said, "To Cristina, George, Izzie and Alex. That we would all move back to Seattle after med school. For our internships and residencies. I want to go back to Seattle." She set her mouth in a line. "I'm going back to Seattle." She said.

"You should." Derek said. "Everything about you is… Seattle."

"Tell me something." Meredith said.

"Addison wants to get married." He said, wishing he could take the words back as soon as they left his mouth. Meredith swore that her heart stopped beating as her stomach dropped.

"Do you want to get married?" she whispered.

"To Addison?" Derek asked. "I'm not sure." He paused. "I don't think so." Meredith looked up at him with wide eyes. "Don't tell her." Derek said.

"We should go." Meredith responded.

* * *

"Fuck." Mark Sloan muttered under his breath as he paid for his coffee. "Fuck." Marriage. When he met Meredith, he was taken by surprise. She was feisty and brilliant, and gorgeous, and didn't just follow him around waiting for him to tell her what was going to happen like the rest of his girlfriends.

When he proposed to her, he thought he was ready. He convinced himself that the things he thought about Addison were just in his head. Now he thought he might be wrong. She was all he could think about. His head was completely consumed with her firey hair, porcelain skin, and patrician features.

"Fuck." He said again.

"And good evening to you too." Addison said, sailing by in her scrubs and cloud of perfume.

"Addie." Mark breathed, relived to see her there. She looked at him. He looked back and her and made a decision. He winked suggestively and leaned in close to her. "Find me later." He whispered, feeling her shiver.

* * *

They rode the elevator in silence. She got off quickly, not sure why she felt so uncomfortable.

"Mer." Derek said, reaching for her wrist as she fumbled for her keys. Her turned her gently towards him and held out his arms. She stepped into them willingly, let him envelop her in a hug. "It's all going to work out. You know that right?"

She was going to respond, but a voice propelled her out of Derek's arms. "You are in so much trouble."

"Cristina?"


End file.
